Re: [RFC PATCH 2/3] net: sparx5: Add Sparx5 switchdev driver

From: Andrew Lunn
Date: Fri Nov 27 2020 - 12:15:29 EST


This is a very large driver, which is going to make it slow to review.

> +static int sparx5_probe_port(struct sparx5 *sparx5,
> + struct device_node *portnp,
> + struct phy *serdes,
> + u32 portno,
> + struct sparx5_port_config *conf)
> +{
> + phy_interface_t phy_mode = conf->phy_mode;
> + struct sparx5_port *spx5_port;
> + struct net_device *ndev;
> + struct phylink *phylink;
> + int err;
> +
> + err = sparx5_create_targets(sparx5);
> + if (err)
> + return err;
> + ndev = sparx5_create_netdev(sparx5, portno);
> + if (IS_ERR(ndev)) {
> + dev_err(sparx5->dev, "Could not create net device: %02u\n", portno);
> + return PTR_ERR(ndev);
> + }
> + spx5_port = netdev_priv(ndev);
> + spx5_port->of_node = portnp;
> + spx5_port->serdes = serdes;
> + spx5_port->pvid = NULL_VID;
> + spx5_port->signd_internal = true;
> + spx5_port->signd_active_high = true;
> + spx5_port->signd_enable = true;
> + spx5_port->flow_control = false;
> + spx5_port->max_vlan_tags = SPX5_PORT_MAX_TAGS_NONE;
> + spx5_port->vlan_type = SPX5_VLAN_PORT_TYPE_UNAWARE;
> + spx5_port->custom_etype = 0x8880; /* Vitesse */
> + conf->portmode = conf->phy_mode;
> + spx5_port->conf.speed = SPEED_UNKNOWN;
> + spx5_port->conf.power_down = true;
> + sparx5->ports[portno] = spx5_port;


> +struct net_device *sparx5_create_netdev(struct sparx5 *sparx5, u32 portno)
> +{
> + struct net_device *ndev;
> + struct sparx5_port *spx5_port;
> + int err;
> +
> + ndev = devm_alloc_etherdev(sparx5->dev, sizeof(struct sparx5_port));
> + if (!ndev)
> + return ERR_PTR(-ENOMEM);
> +

...

> + err = register_netdev(ndev);
> + if (err) {
> + dev_err(sparx5->dev, "netdev registration failed\n");
> + return ERR_PTR(err);
> + }

This is one of the classic bugs in network drivers. As soon as you
call register_netdev() the interface is live. The network stack can
start using it. But you have not finished initialzing spx5_port. So
bad things are going to happen.

Andrew